JPH08241386A - Noncontact memory card and electromagnetic coupling device mountable on same - Google Patents

Abstract

PURPOSE: To provide the noncontact memory card which is small-sized and can transmit signals with high reliability and the electromagnetically coupled device which is applied to an electronic device like this. CONSTITUTION: A coil part for electric power and a coil part for signals are composed of magnetic cores 3a to 3j and coils 2a to 2j wound around the magnetic cores. Magnetic shield materials 52 and 52 are interposed between the magnetic core 3j constituting the coil part for electric power and the coil part for signals which adjoins to it. The tip parts of those magnetic shield materials 51 and 52 are projected from the opposite surfaces of the magnetic cores that face another electromagnetically coupled device. The magnetic shield material 51 is formed of a material which is large in eddy current loss like a metallic material and the magnetic shield material 52 is formed of a material which is high in magnetic absorptivity like a laminate of a magnetic body and a nonmagnetic body.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a non-contact type memory card and an electromagnetic coupling device for transmitting and receiving signals and electric power between the memory card and a terminal device, and more particularly to a signal coil portion and a power device. The present invention relates to means for preventing magnetic interference that occurs between the coil portion and the coil portion.

[0002]

2. Description of the Related Art In recent years, a memory card, which is a type of IC card, has been used as an electronic notebook database, an external recording medium of a computer, an additional memory, etc., and its demand and field of use have expanded dramatically. are doing.
There are a pin insertion method and a non-contact method as a method of coupling the memory card and the terminal device. The pin insertion method is a method for electrically connecting the male connector by inserting the pin provided in the male connector into a socket provided in the female connector. Since they can be exchanged, 8-bit or 16-bit parallel data transfer is possible, which has the advantage that signals can be read and written at high speed, but the pins and sockets are exposed to the outside, so contact due to contamination There is also a drawback that it is easy to cause deterioration of insertion / removal resistance due to defects and miniaturization of pins. On the other hand, the non-contact method uses light,
It is a method of transmitting and receiving signals and supplying power using energy such as electromagnetic or radio waves.Because the conductor is not exposed to the outside, the above problems do not occur, especially in a dirty environment. Since it is advantageous to use, it has been put to practical use in various fields.

As described above, as a method of supplying power and transmitting and receiving signals in a contactless manner, an optical method, an electromagnetic coupling method, a radio wave method and the like have been proposed, but they can be implemented at low cost and consume power. At present, the electromagnetic coupling method is most often used because of its small size. FIG.
FIG. 1 shows the electronic component mounting state of a contactless memory card provided with a conventionally known electromagnetic coupling type connector.

The non-contact memory card of this example is, for example, an SRAM card using a multi-channel type electromagnetic coupling device, and the printed circuit board 5 has coils 2a, 2b ,.
Magnetic cores 3a, 3b, 3 in which 2c, 2d, 2e, 2f, 2g, 2h, 2i, 2j are wound a predetermined number of turns, respectively.
c, 3d, 3e, 3f, 3g, 3h, 3i, 3j, amplifiers 16a, 16b, 16c, 16d for amplifying the signal received by each coil to a predetermined voltage, and a comparator for converting the amplified signal into a digital waveform. 17a, 17b,
17c, a control IC 15 for controlling reading / writing of data, memory ICs 9a, 9b such as SRAM for storing data, and batteries 8a, 8b for holding the data stored in the memory ICs 9a, 9b.
And a power conversion IC 18 that rectifies the power supplied by AC into DC and stabilizes it at a constant voltage.

The magnetic cores 3a, 3b, 3c, 3d, 3e,
Coils 2a, 2b, 2c wound around 3f, 3g, 3h,
2d, 2e, 2f, 2g, and 2h are for exchanging 8-bit data signals and address signals in parallel format, and the coil 2i wound around the magnetic core 3i is for receiving command signals such as read and write. Therefore, the number of windings is the same. On the other hand, the magnetic core 3j
The coil 2j wound on the coil receives electric power and a clock, and has a larger number of windings than the other coils 2a to 2j so as to stably receive electric power. Along with this, the magnetic core 3j becomes the other magnetic core 3a.
It is larger than ~ 3j. The magnetic core 3j
There is also a method of using a plurality of electric power coil portions in addition to the method of enlarging the size.

According to the above-mentioned structure, the multi-channel method enables simultaneous exchange of multi-bit signals, which enables high-speed data transfer.

FIG. 14 is a perspective view of a non-contact memory card having a built-in substrate on which electronic parts are mounted. As is clear from this figure, in the actual machine, the magnetic cores 3a to 3j
Instead of individually arranging the coils 2a to 2j wound on the short side portion of the non-contact memory card 20, the electromagnetic coupling device 10 in which the coils 2a to 2j are integrated by molding is used. It is arranged on the short side of the memory card 20.

As shown in the enlarged view of FIG. 15, the electromagnetic coupling device 10 includes magnetic cores 3a, 3b and 3c around which coils 2a, 2b and 2c are wound, for example, a core support 21 made of a copper plate.
After bonding the above in a predetermined arrangement and electrically connecting the ends of each coil to the external lead 22 made of, for example, a copper plate,
For example, it is manufactured by integrally molding with an epoxy resin 24 containing a SiO ₂ filler. In this configuration, since the whole is molded with resin, foreign matter and moisture do not enter from the outside, and the internal parts are mechanically protected, so a more reliable electromagnetic coupling device. Can be

The contactless memory card 20 provided with the electromagnetic coupling device 10 is inserted into a terminal device 30 for use as shown in FIG. The terminal device 30 is provided with an insertion port 25 for the non-contact memory card 20 on the side surface thereof, and in the back of the terminal device 30, for exchanging signals in opposition to the electromagnetic coupling device 10 attached to the non-contact memory card 20. The terminal side electromagnetic coupling device 10 'is installed. This terminal side electromagnetic coupling device 10 'is also configured in the same manner as the electromagnetic coupling device 10 described above, except that the arrangement of the coil portions is reversed.

FIG. 17 shows an electromagnetic coupling device 10 on the non-contact memory card 20 side and an electromagnetic coupling device 10 'on the terminal device 30 side.
The state of the electromagnetic coupling performed between the terminal device 30 and the contactless memory card 20 will be described as an example.

When a current 11 'flows through the power coil 2'built into the electromagnetic coupling device 10' on the terminal device 30 side, a magnetic flux 12 'is generated in the magnetic core 3'. The generated magnetic flux jumps over the core gap Gc and flows into the magnetic core 3 built in the electromagnetic coupling device 10 on the opposite side of the non-contact memory card 20 side, and is linked to the coil 2 wound around the magnetic core 3 to induce the induced current 11. To occur. Thereby, power can be supplied to the non-contact memory card 20.

By the way, the core gap portion has a relative magnetic permeability of 1/100 to 1/1000 as compared with the magnetic cores 3 and 3 '.
Since it is low, the magnetic resistance is large, and a part of the magnetic flux 12 ′ becomes leakage magnetic flux 13, 13 ′ that does not interlink with the coil 2. Magnetic flux 12 'and coil 2 generated when exciting coil 2'
The ratio of the magnetic fluxes that link to is called the coupling coefficient. Leakage magnetic flux 13
Since the increase of a and 13b lowers the coupling coefficient, it is necessary to reduce the presence of Gc in the core gap as much as possible in order to increase the coupling coefficient.

The electromagnetic coupling device 10, 1 having the above-mentioned conventional structure
Between 0 ′, the core gap Gc is represented by 2t + Ga. Here, t is the wall thickness of the mold, and Ga is an air gap that is inevitably generated due to external dimension errors and alignment errors of the electromagnetic coupling devices 10 and 10 ′. The air gap Ga is generally about 0.1 to 0.2 mm, and the mold wall thickness t needs to be about 0.2 mm in order to secure mechanical strength and molding accuracy. A core gap Gc of at least about 0.5 mm is generated between the electromagnetic coupling devices 10 and 10 '.

FIG. 18 shows the relationship between the core gap Gc and the coupling coefficient in a coil configuration of a general size incorporated in the electromagnetic coupling device. As is clear from this figure, the coupling coefficient (power transmission efficiency) at the core gap Gc = 0.5 mm is about 0.3, and the electromagnetic coupling device 1 having the conventional structure is used.
It can be seen that between 0 and 10 ', only about 30% of electric power can be transmitted, and 70% of energy is lost.

[0015]

As described above, in the power coil section, the magnetic core is larger in size and the number of windings of the coil is larger than that of the signal coil section, and a plurality of coils are assembled. Formed from the body, it produces a high level of leakage flux. Conventionally, a non-magnetic spacer 4i is provided between the power coil section and the signal coil section,
Although the adverse effect of the magnetic flux leaked from the power coil section on the signal coil section has been mitigated, for example in an electromagnetic coupling device for a non-contact memory card etc. It is impossible to set a spacer 4i having a size large enough to prevent the adverse effect of the magnetic flux between the coil portions. Therefore, in the conventional electromagnetic coupling device, the leakage magnetic flux from the power coil unit is likely to be superimposed on the magnetic signal generated from the signal coil unit, which may hinder accurate signal transmission.

The present invention has been made in order to solve the deficiencies of the prior art, and its object is to provide an electromagnetic coupling device which is small in size and has excellent signal transmission characteristics. An object is to provide a contactless memory card equipped with an electromagnetic coupling device.

[0017]

In order to achieve the above object, the present invention provides a data storage memory and transmission / reception of a signal between a partner device and the data storage memory by electromagnetic coupling, and a signal from the partner device. In a contactless memory card including an electromagnetic coupling device that receives and supplies electric power, a signal coil unit and a power coil unit are provided between a signal coil unit and a power coil unit that form the electromagnetic coupling device. A magnetic shield material is arranged so as to project to the opposite coil portion side from the surface of the magnetic core to be formed. Further, regarding the electromagnetic coupling device, an electromagnetic coupling device that includes a signal coil portion and a power coil portion, and that transmits and receives a signal to and from the partner signal coil portion and the power coil portion by electromagnetic coupling A structure in which a magnetic shield material projecting from the surface of the magnetic core forming the signal coil portion and the power coil portion to the opposite coil portion side is arranged between the signal coil portion and the power coil portion. I chose

[0018]

The gap between the magnetic shield materials provided in the two electromagnetic coupling devices electromagnetically coupled to each other and the magnetic mutual interference (crosstalk) generated between the signal coil portion and the power coil portion. There is a close relationship between them, and the smaller the gap, the more the crosstalk decreases as a quadratic function. On the other hand, if the tip end portion of the magnetic shield material is arranged behind the magnetic cores forming the signal coil portion and the power coil portion, the effect of providing the magnetic shield material is lost. Therefore, between the coil portion for signal and the coil portion for electric power, the magnetic shield material is formed so as to protrude outside the surface of the magnetic core forming the coil portion for signal and the coil portion for electric power facing the counterpart coil portion. By providing, it is possible to mitigate crosstalk that occurs between the signal coil unit and the power coil unit, and it is possible to realize highly reliable signal transmission.

Since the contactless memory card is required to be small and thin, the electromagnetic coupling device mounted on the contactless memory card has a sufficient size between the power coil portion and the signal coil portion. Space cannot be provided. As described above, by providing the magnetic shield material protruding between the signal coil portion and the power coil portion to the outside of the surface facing the counterpart coil portion, a sufficient crosstalk reduction effect can be obtained in a small space. Therefore, a non-contact memory card capable of highly reliable signal transmission can be constructed.

[0020]

【Example】

<First Embodiment> An electromagnetic coupling device according to a first embodiment will be described with reference to FIGS. FIG. 1 is a plan view of an electromagnetic coupling device according to this embodiment, FIG. 2 is an explanatory diagram showing a state of magnetic flux during signal or power transmission, and FIG. 3 is a diagram illustrating coupling between a thickness of a high-permeability magnetic plate and a core gap of the electromagnetic coupling device. FIG. 4 is a graph showing a relationship between coefficient increase rates, and FIG. 4 is a perspective view showing an example of mounting on a non-contact memory card.

As shown in FIG. 1, the electromagnetic coupling device 1 of this example.
0 is the magnetic core 3a wound with the coil 2a, the coil 2
a magnetic core 3b in which b is wound, a magnetic core 3c in which a coil 2c is wound, a magnetic core 3d in which a coil 2d is wound,
The magnetic core 3e wound with the coil 2e, the magnetic core 3f wound with the coil 2f, the magnetic core 3g wound with the coil 2g, the magnetic core 3h wound with the coil 2h, and the coil 2i are wound. The magnetic core 3i and the magnetic core 3j around which the coil 2j is wound are respectively provided with spacers 4a, 4b, 4c,
4d, 4e, 4f, 4g, 4h, 4i and an adhesive layer (not shown) are connected to each other, and the entire surface can be covered with a surface of the manufactured rectangular rod-shaped coil assembly 40 facing the counterpart electromagnetic coupling device. A plate-shaped high-permeability magnetic plate 1 having a size and shape is adhered.

As shown in FIG. 1, the magnetic cores 3a to 3j are formed in a substantially U shape in a plan view, and are disposed on both sides of the winding core through a recess for winding formed in the center. The surface facing the counterpart electromagnetic coupling device is formed in the same plane. Each of the magnetic cores 3a to 3j has a relative magnetic permeability of 100 to 10 such as Mn-Zn ferrite or Ni-Zn ferrite in order to efficiently transmit the magnetic flux.
It is formed of a magnetic material having a high magnetic permeability of about 00. The coils 2a to 2j are formed, for example, by winding a copper wire coated with an insulating material around the winding recesses of the magnetic cores 3a to 3j. The spacers 4a to 4i are inserted between the coils in order to keep the adjacent coils at a distance where they do not magnetically interfere with each other, and are formed of a non-magnetic material such as barium titanate or calcium titanate. It The high-permeability magnetic plate 1 relaxes the magnetic resistance in the core gap portion and improves the transmission efficiency. For example, a soft magnetic metal oxide powder such as Mn-Zn ferrite or Ni-Zn ferrite is used as PBT ( A resin such as polybutylene terephthalate) or PPS (polyphenylene sulfide) or an elastomer such as an olefin-based or urethane-based resin and dispersed into a predetermined size and shape is used. As the high-permeability magnetic plate 1, any plate having a relative magnetic permeability of 1 or more can be used, but usually 1
Adjusted to ~ 30.

As shown in FIG. 2, the electromagnetic coupling device 10 of this embodiment is arranged opposite to the electromagnetic coupling device 10 'provided on the terminal device side, and transmits and receives signals and supplies power. Taking the case of supplying power as an example, the electromagnetic coupling device 10, 1
Explaining the state of the magnetic flux between 0 ', when the exciting current 11' flows through the power coil 2'of the electromagnetic coupling device 10 'on the terminal device side, the magnetic flux 12 according to the magnetic resistance of the magnetic path formed by this system is generated. 'Occurs. In the electromagnetic coupling devices 10 and 10 ′ of this example, a high magnetic permeability magnetic plate having a relative magnetic permeability higher than that of air (relative magnetic permeability μ = 1) is arranged on the opposing surface, so The magnetic resistance of the core gap Gc becomes smaller than that of the conventional electromagnetic coupling device in which a mold resin having a magnetic permeability substantially the same as that of air is arranged, and a larger magnetic flux 12 'is generated. Further, since the magnetic resistance of the core gap Gc is relaxed, the electromagnetic coupling device 10 jumped over the core gap Gc and incorporated in the memory card.
The ratio (coupling coefficient) of the magnetic flux 12 interlinking with the electric power coil 2 built in is larger than in the conventional case. Therefore, a larger induced current 11 is generated in the power coil 2, and the proportion of the leakage magnetic flux 13a, 13b that does not contribute to electromagnetic coupling is reduced. The thickness t of the high-permeability magnetic plate 1 is preferably as thick as possible in order to ensure mechanical strength, but if it is made thicker than necessary, the magnetic resistance of the magnetic path of the leakage magnetic flux 13a becomes small and the coupling coefficient decreases. Therefore, it is desirable to set the thickness to about 0.15 to 0.25 mm, which is the minimum thickness necessary to ensure the mechanical strength.

FIG. 3 shows an electromagnetic coupling device having a high-permeability magnetic plate 1 having a thickness t of 0.25 mm and a relative magnetic permeability μ of 10.
Core gap Gc in an electromagnetic coupling device having a high-permeability magnetic plate 1 having a thickness t of 0.25 mm and a relative permeability μ of 30.
And the increase rate of the coupling coefficient. Here, the rate of increase in the coupling coefficient means the rate of increase in the coupling coefficient when compared with an electromagnetic coupling device having a conventional structure without the high-permeability magnetic plate 1.

As is clear from this figure, when the core gap Gc is 0.5 mm, that is, when the electromagnetic coupling devices are in close contact with each other and the air gap Ga (space) is 0, the coupling coefficient is almost twice that of the conventional structure. Increase to. Also, the air gap G
Considering that a occurs inevitably in the range of 0.1 to 0.2 mm due to the outer dimension error and the positioning error of the electromagnetic coupling device, the core gap Gc = 0.6 to 0. It is performed at 7 mm. Therefore, in this case, the electromagnetic coupling device having the high magnetic permeability magnetic plate 1 having a relative magnetic permeability μ of 10 has a higher coupling coefficient than the electromagnetic coupling device having the high magnetic permeability magnetic plate 1 having a relative magnetic permeability μ of 30. This is appropriate because it exceeds the rate of increase and is improved by about 40% from the conventional level. As described above, the preferable relative permeability μ of the high-permeability magnetic plate 1 changes depending on the thickness of the high-permeability magnetic plate 1 and the coil configuration. Therefore, an appropriate value of 1 or more is selected in consideration of these factors. It is desirable to do.

FIG. 4 shows an example of mounting the electromagnetic coupling device configured as described above on a multi-channel contactless memory card. In this example, the electromagnetic coupling device 10 is arranged at an end portion on the short side of the printed circuit board 5 on which electronic components such as the memory ICs (for example, SRAM) 9a, 9b, 9c and the data storage battery 8 are mounted. There is. The electromagnetic coupling device 10 and the printed circuit board 5 are connected to the card frame 6
It is housed in a card case composed of a card name plate 7 and a non-contact memory card. The high-permeability magnetic plate 1 attached to the facing surface of the electromagnetic coupling device 10 is exposed to the outside through a window hole formed in the card case, and its set position is set on the card frame 6 and the card name plate 7. It is adjusted so that it is the same as the end face or slightly protrudes beyond this.

In the electromagnetic coupling device of this embodiment, the high magnetic permeability magnetic plate 1 made of a magnetic material having a relative magnetic permeability greater than 1 is arranged on the opposing surfaces of two electromagnetic coupling devices which are electromagnetically coupled to each other. The relative permeability in the gap Gc is improved,
As a result of reducing the leakage magnetic flux, the transmission efficiency of the signal coil portion and the power coil portion is improved. Therefore, the signal coil portion and the power coil portion can be downsized, the design can be facilitated, and the non-contact type memory card can be highly functionalized by further increasing the number of channels. Further, since the single high-permeability magnetic plate 1 covers all the facing surfaces of the signal coil portion and the power coil portion, this high-permeability magnetic plate 1 exerts a function as a protective plate. It is possible to prevent disconnection of the coil and damage to the coil assembly 40 due to collision of foreign matters. Furthermore, by adhering the signal coil portion, the power coil portion, and the high-permeability magnetic plate 1 to the card frame 6 and the card name plate 7, it is possible to prevent the intrusion of moisture from the outside.

In the above embodiment, the high magnetic permeability magnetic plate 1 is provided in both the electromagnetic coupling device 10 provided in the contactless memory card and the electromagnetic coupling device 10 'provided in the terminal device. Even if the high-permeability magnetic plate 1 is attached to only one of them, it is effective in improving the transmission efficiency.

Further, in the above-mentioned embodiment, the high magnetic permeability magnetic plate 1 is formed in a shape covering the entire facing surface of the coil assembly 40, but in the case where moisture intrusion or foreign substance invasion from the outside does not pose a problem. In the above, the high-permeability magnetic plate 1 can be formed smaller than the facing surface of the coil assembly 40.

In addition, the shape, size, material, etc. of each part constituting the electromagnetic coupling devices 10 and 10 'can be arbitrarily designed regardless of the above embodiment. For example, in the above-described embodiment, the signal coil portion and the power source coil portion are integrally formed as the electromagnetic coupling device 10 or 10 ', but each of these coil portions may be configured as an independent separate body. . Further, in the above embodiment, the plurality of magnetic cores constituting each coil portion and the coil wound around the magnetic cores are integrally formed. However, these individual magnetic cores and coils may be formed as separate bodies. You can also

<Second Embodiment> A second embodiment of the present invention will be described with reference to FIGS. FIG. 5 is a plan view of a main part showing a mounted state of the electromagnetic coupling device according to the present embodiment, and FIG. 6 is an exploded perspective view showing a component structure of a contactless memory card.

As is apparent from FIG. 5, the electromagnetic coupling device of this embodiment is characterized in that the high-permeability magnetic plate 1 attached to the facing surface of the coil assembly 40 is extended to the side end of the card case. And In this example, the end surface of the coil assembly 40 is arranged on the same plane as the end surfaces of the card frame 6 and the card name plate 7. The high-permeability magnetic plate 1 is previously bonded to the tip end surface of the coil assembly 40, and the coil assembly 4
0 and the printed circuit board 5 are housed in a card case composed of a card frame 6 and a card name plate 7, and then both ends of the high magnetic permeability magnetic plate 1 can be adhered to the end surface of the card case. The high magnetic permeability magnetic plate 1 may be adhered to the end faces of the coil assembly 40 and the card case after the coil assembly 40 and the printed circuit board 5 having no magnetic susceptibility magnetic plate 1 are housed in the card case. Since the other parts are the same as those of the electromagnetic coupling device of the first embodiment, the corresponding parts are designated by the same reference numerals and the description thereof will be omitted.

The electromagnetic coupling device of the present example has the same effect as the electromagnetic coupling device according to the first embodiment, and since the high magnetic permeability protection plate 1 is installed outside the card case, the card case is completely sealed. Since it is possible to prevent the intrusion of moisture and the like, the contactless memory card can be made more reliable.

<Third Embodiment> FIG. 7 is a plan view of a principal portion showing a mounted state of an electromagnetic coupling device according to a third embodiment. The electromagnetic coupling device of this example is characterized in that high-permeability magnetic plates 1a and 1b having different relative magnetic permeability are installed in the power coil unit and the signal coil unit incorporated therein.

Since the signal coils 2a to 2i have a risk of causing magnetic mutual interference between adjacent coils, the spacer 4a has a degree to which signal crosstalk can be ignored.
Each coil is spatially separated by ~ 4g. However, when a high-permeability magnetic plate is placed in the signal coil section, the magnetic resistance of the core gap section is relaxed, the signal transfer efficiency is improved, and at the same time, magnetic mutual interference between adjacent coils is strengthened, resulting in signal crosstalk. Is more likely to occur. Therefore, in the present embodiment, the first high-permeability magnetic plate 1a having a large relative permeability is arranged in the portion facing the power coil portion so that necessary power can be transmitted, and the signal coil is used. A second high-permeability magnetic plate having a relative magnetic permeability smaller than that of the first high-permeability magnetic plate 1a is provided in a portion facing the portion in order to improve signal transfer efficiency and at the same time prevent signal crosstalk. 1b is arranged.

The first high-permeability magnetic plate 1a and the second high-permeability magnetic plate 1b can be formed as independent bodies or can be integrally formed.
Further, also in the electromagnetic coupling device of the present example, similar to the electromagnetic coupling device according to the second embodiment, the high magnetic permeability magnetic plates 1a and 1a are provided.
It is also possible to form b to be longer than the coil assembly 40 and to install it on the outside of the card case. Since the other parts are the same as those of the electromagnetic coupling device of the first embodiment, the corresponding parts are designated by the same reference numerals and the description thereof will be omitted.

The electromagnetic coupling device of this embodiment has the same effects as the electromagnetic coupling devices of the first and second embodiments, and the ratio of the high magnetic permeability magnetic plate 1 to the power coil portion and the signal coil portion is high. Since the magnetic permeability is changed, power and signal transfer efficiency can be improved, and at the same time, signal crosstalk can be prevented.

<Fourth Embodiment> FIG. 8 is a plan view of a principal portion showing a mounted state of an electromagnetic coupling device according to a fourth embodiment. The electromagnetic coupling device of the present example is characterized in that the high-permeability magnetic plate 1 is arranged only in the power coil portion incorporated therein and the non-magnetic protective plate 14 is arranged in the signal coil portion.

The power coil section requires the high-permeability magnetic plate 1 in order to enable the supply of necessary power with a small coil, but the signal coil section requires the number of windings and the magnetic core. By adjusting the size, the material, etc., the signal transmission / reception may be stably performed without the high-permeability magnetic plate 1. Further, when the high-permeability magnetic plate 1 is provided in the signal coil portion, signal crosstalk may occur due to magnetic mutual interference between the adjacent signal coils as described above. Therefore, in this embodiment, a high-permeability magnetic plate 1 having a relative magnetic permeability greater than 1 is arranged in the portion facing the power coil portion so that necessary power can be transmitted, and the signal coil is used. In the part facing the part,
A non-magnetic protective plate 14 having a relative magnetic permeability of about 1, which is the same as that of air, is arranged. As the non-magnetic protective plate 14, for example, a resin plate having the same thickness as the high-permeability magnetic plate 1, such as a polyethylene terephthalate plate or a polycarbonate plate, which is excellent in mechanical properties and weather resistance, is suitable.

The high-permeability magnetic plate 1 and the non-magnetic protective plate 14 can be formed as independent bodies, or can be integrally formed. Also in the electromagnetic coupling device of the present example, the high magnetic permeability magnetic plate 1 and the non-magnetic protection plate 14 are formed to be longer than the coil assembly 40, as in the electromagnetic coupling device according to the second embodiment. It can also be installed outside the card case. For other parts,
Since this is the same as the electromagnetic coupling device of the first embodiment, the corresponding parts are designated by the same reference numerals and the description thereof is omitted.

The electromagnetic coupling device of this example has the same effects as the electromagnetic coupling devices according to the first and second embodiments, and in addition, the high permeability magnetic plate 1 is provided only in the power coil portion, and the signal coil portion is provided. Since the non-magnetic protective plate 14 is provided in the device, the power transfer efficiency can be improved, and at the same time, signal crosstalk can be prevented.

<Fifth Embodiment> An electromagnetic coupling device according to a fifth embodiment will be described with reference to FIGS. 9 is a plan view of a main part of a coupling state of the electromagnetic coupling device on the power receiving side and the electromagnetic coupling device on the power supplying side, FIG. 10 is a graph showing the effect of the electromagnetic coupling device according to this example, and FIG. Is a graph showing the relationship between the power supply noise and the distance from the magnetic shield metal plate to the magnetic shield, and FIG. As shown in FIG. 9, the electromagnetic coupling device of this example is characterized in that magnetic shield plates 51 and 52 are provided between a power coil unit and a signal coil unit incorporated therein.

The magnetic core 3j forming the power coil portion of the electromagnetic coupling device on the power supply side is formed larger than the magnetic cores 3a, 3b, 3c, ... The coil 2j that constitutes the signal coil portion includes coils 2a, 2b, 2c, ...
There are more windings than Therefore, a lot of leakage magnetic flux is generated from the power coil portion of the electromagnetic coupling device on the power supply side, and if this is left as it is, the magnetic field generated from the signal coil portion will have a leakage magnetic field from the power coil portion. Overlapping may interfere with accurate signal transmission.
Therefore, in this embodiment, the magnetic shield plates 51 and 52 are provided between the power coil portion and the signal coil portion to remove or reduce the influence of the leakage magnetic flux.

Magnetic shield plate 51 on the power coil side
Is composed of a conductive material having a large eddy current loss, that is, a small resistivity, such as sendust, permalloy, copper, aluminum, carbon, and a metal oxide having superconducting properties. On the other hand, the magnetic shield plate 52 on the signal coil side is, for example, a soft magnetic material such as Mn—Zn ferrite or a laminated body of the soft magnetic material such as Mn—Zn ferrite and a non-magnetic material such as paper. For example, it is formed of a high magnetic permeability material that easily absorbs magnetic flux.

The tip portions 51a, 52a of these two magnetic shield plates 51, 52 are formed by magnetic cores 3a, 3b, 3c,
It is formed so as to project outward from the surface facing the other party's electromagnetic coupling device. The reason will be described with reference to FIG.

FIG. 10 shows magnetic shield plates 51, 52 and 5 provided in two electromagnetic coupling devices coupled to each other.
1 shows the relationship between the size of the gap Gs between 1'and 52 'and the power supply noise flowing into the signal coil section, and the gap between the magnetic cores of the power coil sections and the signal coil section which are coupled to each other. Gc of the magnetic core is 0.5m
It was measured as m.

As is clear from this figure, the gap Gs
Is smaller than the gap Gc between the magnetic cores arranged opposite to each other, that is, the magnetic shield plate 5
The tip portions 51a and 52a of the magnetic cores 1 and 52 are magnetic cores 3a and 3
When the protrusions b, 3c, ... Are outwardly projected from the surface facing the counterpart electromagnetic coupling device, the noise due to crosstalk is significantly reduced, and the smaller the gap Gs, the more the crosstalk decreases. effective. This is based on the fact that, of the magnetic force lines generated from the power supply coil, the magnetic force lines toward the signal coil are blocked by the magnetic shield plates 51 and 52. When the gap Gs is 0.5 mm or less, noise due to crosstalk can be -20 dB or less. If the noise due to crosstalk can be reduced to -20 dB or less, it can be removed by devising a signal detection system, so that noise due to crosstalk does not pose a problem in practical use.

Of the two magnetic shield plates 51, 52, the first one made of a metal material having a large eddy current loss.
As is clear from FIGS. 9 and 11, the magnetic shield plate 51 of FIG. 11 constitutes the signal coil portion as the distance d ₁ to the magnetic core 3j constituting the power source coil portion which is the source of noise decreases. Since the power source noise flowing into the magnetic core 3a and the like is reduced, it is preferable to install the magnetic core 3a at a position closer to the magnetic core 3j. On the other hand, the second magnetic shield plate 52 formed of a material that easily absorbs magnetic flux has a distance d ₁ to the magnetic core 3j forming the power supply coil portion, as is clear from FIGS. 9 and 12. The larger the value, the smaller the power noise that flows into the magnetic core 3a or the like that constitutes the signal coil portion.

Therefore, it is possible to reduce the noise by arranging the first magnetic shield plate 51 and the second magnetic shield plate 52 in this order between the power supply coil portion and the signal coil portion, which are sources of noise. Most effective in.

However, the second magnetic shield plate 52 made of a material that easily absorbs magnetic flux is provided on the power coil side, and the first magnetic shield plate 51 made of a metal material having a large eddy current loss.
Since the noise reduction effect can be obtained to some extent even if the magnetic shield plates 51 and 52 are arranged on the signal coil side, the magnetic shield plates 51 and 52 can be arranged in this way, if necessary. Further, in the fifth embodiment, the two magnetic shield plates 51 and 52 are provided between the coil portions, but depending on the magnitude and frequency of the leakage magnetic flux generated from the power coil portion,
It suffices if one of the magnetic shield plates is provided. Furthermore, in the above embodiment, the magnetic shield plates are provided on both the power receiving side and the power supply side. However, even if the magnetic shield plates are provided only on the power supply side, a sufficient effect for reducing crosstalk can be obtained. is there.

The electromagnetic coupling device of this example is also mounted on a non-contact memory card as shown in FIG. 4, for example. The mounting method is the same as in the first embodiment. Also, regarding the shape, dimensions, materials, etc. of each part that constitutes the electromagnetic coupling device,
Like the first embodiment, it can be designed arbitrarily. For example,
Signal coil part, power supply coil part, and magnetic shield plate 5
1, 52 can be formed integrally, or they can be configured as independent separate bodies. Further, it is possible to integrally form a plurality of magnetic cores forming the signal coil portion and the coil wound around the magnetic cores, or to form these separately as separate bodies. Further, as described in the section of the first to fourth embodiments, the high-permeability magnetic plate and / or the non-magnetic protective plate are provided on the surfaces of the power coil portion and the signal coil portion facing the counterpart electromagnetic coupling device. Can be selectively attached.

The electromagnetic coupling device of the present invention can be mounted on a non-contact memory card and can be applied to any other electronic device.

[0053]

As described above, according to the present invention, between the signal coil portion and the power coil portion, the tip end portion of the magnetic coil portion constitutes the signal coil portion and the power coil portion. Since the magnetic shield material projecting from the surface of the core that faces the other electromagnetic coupling device is provided, crosstalk that occurs between the signal coil portion and the power coil portion can be mitigated. Therefore, it is possible to provide a contactless memory card that is compact and capable of highly reliable signal transmission, and an electromagnetic coupling device applied to such an electronic device.

[Brief description of drawings]

FIG. 1 is a plan view of an electromagnetic coupling device according to a first embodiment.

FIG. 2 is an explanatory diagram showing a state of magnetic flux at the time of signal or power transmission of the electromagnetic coupling device according to the first example.

FIG. 3 is a graph showing the relationship between the thickness of the high-permeability magnetic plate, the core gap of the electromagnetic coupling device, and the coupling coefficient increase rate.

FIG. 4 is a perspective view showing a mounting example of the electromagnetic coupling device according to the first embodiment.

FIG. 5 is a main part plan view showing an example of mounting the electromagnetic coupling device according to the second embodiment.

FIG. 6 is an exploded perspective view showing a component configuration of a non-contact memory card.

FIG. 7 is a main-portion plan view showing a mounting example of the electromagnetic coupling device according to the third embodiment;

FIG. 8 is a main-portion plan view showing a mounting example of the electromagnetic coupling device according to the fourth embodiment;

FIG. 9 is a plan view of an essential part of an electromagnetic coupling device according to a fifth embodiment.

FIG. 10 is a graph showing effects of the electromagnetic coupling device according to the fifth embodiment.

FIG. 11 is a graph showing the relationship between the distance from the power supply coil to the magnetic shield metal plate and the power supply noise.

FIG. 12 is a graph showing the relationship between the distance from the power supply coil to the magnetic shield soft magnetic material and the power supply noise.

FIG. 13 is a perspective view showing an electronic component mounted state of a non-contact memory card provided with an electromagnetic coupling device according to a conventional example.

FIG. 14 is a perspective view of a contactless memory card including an electromagnetic coupling device.

FIG. 15 is a perspective view of a main part of an electromagnetic coupling device according to a conventional example.

FIG. 16 is a perspective view showing a coupled state of the electromagnetic coupling device provided in the contactless memory card and the electromagnetic coupling device provided in the terminal device.

FIG. 17 is an explanatory diagram showing a state of electromagnetic coupling between electromagnetic coupling devices according to a conventional example.

FIG. 18 is a graph showing the relationship between the size of the core gap and the magnetic coupling coefficient.

[Explanation of symbols]

 1 High Permeability Protection Plate 2a to 2j Coil 3a to 3j Magnetic Core 4a to 4i Spacer 5 Printed Circuit Board 6 Card Frame 7 Card Name Plate 10 Electromagnetic Coupling Device 11 Current 12 Connector 13 Leakage Magnetic Flux

Claims (15)

[Claims] 1. A non-contact memory card provided with a data storage memory and an electromagnetic coupling device for transmitting and receiving a signal between a counterpart device and the data storage memory by electromagnetic coupling and for receiving electric power from the counterpart device. In, between the signal coil portion and the power coil portion constituting the electromagnetic coupling device, the magnetic projecting to the other coil portion side from the surface of the magnetic core constituting the signal coil portion and the power coil portion. A non-contact memory card having a shield material. 2. The contactless memory card according to claim 1, wherein the signal coil portion, the power coil portion, and the magnetic shield material are integrally assembled. 3. The non-contact memory card according to claim 1, wherein the signal coil portion, the power coil portion, and the magnetic shield material are each configured as an independent separate body. Contact memory card. 4. The contactless memory card according to claim 1, wherein at least one of the signal coil portion and the power coil portion is formed as an independent separate body. And a plurality of coils wound around each magnetic core. 5. The contactless memory card according to claim 1, wherein the magnetic shield material is at least one of a conductive material having a low resistivity and a high magnetic permeability material. A non-contact memory card characterized by being used. 6. The contactless memory card according to claim 1, wherein the magnetic shield material comprises a first shield plate made of a conductive material having a low resistivity and a high transparency. And a second shield plate made of a magnetic material, wherein the first shield plate is arranged on the power coil portion side and the second shield plate is arranged on the signal coil portion side. Contactless memory card. 7. The non-contact memory card according to claim 5, wherein the high magnetic permeability material is composed of a laminated body of a high magnetic permeability magnetic material and a non-magnetic material. And a non-contact memory card. 8. The contactless memory card according to claim 1, wherein a protective plate made of a magnetic material or a non-magnetic material is provided on a surface of the power coil section and the signal coil section facing the counterpart coil section. A non-contact memory card characterized by the above. 9. The non-contact memory card according to claim 1, wherein a high permeability protection made of a magnetic material having a relative permeability greater than 1 is provided on a surface of the power coil portion facing the counterpart power coil portion. A non-contact memory card having a plate. 10. An electromagnetic coupling device comprising a signal coil section and a power coil section, for transmitting and receiving a signal to and from a counterpart signal coil section and a power coil section by electromagnetic coupling, wherein the signal is A magnetic shield material is disposed between the power coil portion and the power coil portion so as to project toward the other coil portion side from the surface of the magnetic core forming the signal coil portion and the power coil portion. Electromagnetic coupling device. 11. The electromagnetic coupling device according to claim 10, wherein at least one of a metal material and a high magnetic permeability material is used as the magnetic shield material. 12. The electromagnetic coupling device according to claim 10, wherein the magnetic shield material is a first shield plate made of a conductive material having a low resistivity and a second shield plate made of a high magnetic permeability material. A non-contact memory card, wherein the first shield plate is disposed on the power coil portion side and the second shield plate is disposed on the signal coil portion side. 13. The electromagnetic coupling device according to claim 11, wherein the high magnetic permeability material is composed of a laminated body of a high magnetic permeability magnetic material and a non-magnetic material. Electromagnetic coupling device. 14. The electromagnetic coupling device according to claim 10, wherein a protective plate made of a magnetic material or a non-magnetic material is provided on a surface of the power coil section and the signal coil section facing the counterpart coil section. An electromagnetic coupling device. 15. An electromagnetic coupling device according to claim 10, wherein a high-permeability protection plate made of a magnetic material having a relative magnetic permeability greater than 1 is provided on a surface of the power coil portion facing the counterpart power coil portion. An electromagnetic coupling device comprising: